Sequence of Shiga Toxin 2 Phage 933W from Escherichia coli O157:H7: Shiga Toxin as a Phage Late-Gene Product†
AUTOR(ES)
Plunkett, Guy
FONTE
American Society for Microbiology
RESUMO
Lysogenic bacteriophages are major vehicles for the transfer of genetic information between bacteria, including pathogenicity and/or virulence determinants. In the enteric pathogen Escherichia coli O157:H7, which causes hemorrhagic colitis and hemolytic-uremic syndrome, Shiga toxins 1 and 2 (Stx1 and Stx2) are phage encoded. The sequence and analysis of the Stx2 phage 933W is presented here. We find evidence that the toxin genes are part of a late-phage transcript, suggesting that toxin production may be coupled with, if not dependent upon, phage release during lytic growth. Another phage gene, stk, encodes a product resembling eukaryotic serine/threonine protein kinases. Based on its position in the sequence, Stk may be produced by the prophage in the lysogenic state, and, like the YpkA protein of Yersinia species, it may interfere with the signal transduction pathway of the mammalian host. Three novel tRNA genes present in the phage genome may serve to increase the availability of rare tRNA species associated with efficient expression of pathogenicity determinants: both the Shiga toxin and serine/threonine kinase genes contain rare isoleucine and arginine codons. 933W also has homology to lom, encoding a member of a family of outer membrane proteins associated with virulence by conferring the ability to survive in macrophages, and bor, implicated in serum resistance.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=93574Documentos Relacionados
- Cytolethal Distending Toxin Gene Cluster in Enterohemorrhagic Escherichia coli O157:H− and O157:H7: Characterization and Evolutionary Considerations
- Characterization of the late-gene regulatory region of phage 21.
- The Operator and Early Promoter Region of the Shiga Toxin Type 2-Encoding Bacteriophage 933W and Control of Toxin Expression
- Characterization of a Eukaryotic-Like Tyrosine Protein Kinase Expressed by the Shiga Toxin-Encoding Bacteriophage 933W
- Transduction of Enteric Escherichia coli Isolates with a Derivative of Shiga Toxin 2-Encoding Bacteriophage φ3538 Isolated from Escherichia coli O157:H7